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UNITED STATES PATENT OFFICE.

CARL A. \V. YOLLRA'IH, O l SIIEBOY lAN, VISCONSIN, ASSIGNOR TO THE JACOB .I. YOLLRATII MANUFAC' URlNG COMPANY, OF SAME PLACE.

PROCESS OF ENAMELING METAL SURFACES.

SPECIFICATION forming part of Letters Patent No. 415,485, dated November 19, 1889.

Application filed September 23, 1389. Serial No. 324,813. (No specimens.)

To all 1071 0712 it 71mg concern.-

Be it known that I, CARL A. W. VOLLRA'TH, of Sheboygan, in the county of Sheboygan, and in the State of Wisconsin, have invented certain new and useful. Improvements in the Art of Enameling Metal Surfaces; and I do hereby declare that the following is a full, clear, and exact description thereof.

My invention relates to improvements in the process of enameling metal surfaces, and

will be fully set forth hereinafter and subsequently claimed.

In carrying out my process I proceed as follows: The iron or metal plat-es or other articles to be enameled are first subjected to the ordinary pickling or scouring operations for the purpose of removing the scale and pre paring the surface for the reception of the enameling composition.

I first prepare what I term the ground mass or foundation-coati11g, the same consisting of a mixture of fifty parts of fiint or quartz sand, thirty to sixty parts of borax, and five to ten parts of lime melted together in a suitable crucible, and taken therefrom, cooled, and ground with water into a paste and distributed over the surface of the metallic article by pouring, dipping, or other convenientmean s, and then dried, and the article so coated is then put in a suitable muffie or furnace and subjected to a temperature of about 1200 Fahrenheit. I next prepare the finishing-coating, as follows: I take sixty parts of pulverized feldspar, (mixed, if preferred, with similar sand to that first named,) twentyfive to thirtyfive parts of borax, twenty parts of cryolite, ten to fifteen parts of soda, and five parts of saltpeter, melting this mass and cooling it and grinding it, preferably in a moist condition, (adding clay, if the mass is to be ground fine,) until the whole is of the consistency of paste. This makes what I call mixture A. Next, according to the color desired, I take the necessary ingredient-s-for instance, for blue I take cobalt, for violet, cobalt and manganese, and so on and add said ingredients to a separately-prepared mixture of feldspar, borax, cryolite, soda, and salt-peter in'substantially the same proportions as before, the amount of the coloriug ingredient added being more or less as a light or dark result is desiredsay from one to three per cent.-and this mixture is melted, cooled, and ground dry into a condition like sand, forming my mixture B, this mixture, containing the coloring-matter, being ground to a different degree of fineness from that of the first-named mixture A. I next mix A and l together in the necessary proportion to produce the desired effect, according as the finished product is to have more or less of the color prominent, a good average mixture being one part of mixture B to three parts of mixture A when B is ground coarser than A; but the proportion may be reversed if the mixture A is ground coarser, in which case the clay may be added to B instead of to A, as that substance should be used with the finest grinding. The justmixed mass of A and B is now of a paste-like consistency and is applied by pouring or dipping to the articles having the first-described foum'lation-coating and dried, and then they are put in a muffle and subjected to a temperature of about 1,000 Fahrenheit, which results in the production of a smooth glossy surface having a beautiful mottled appearance.

If desired, the finishing-coating (consisting of mixtures A and B) may be applied directly to the cleaned metallic articles; but ordinarily I prefer to apply a foundationcoating, as first described; but in either event the objectof my present invention is the production automatically upon metal surfaces of a mottled or pleasinglyspeckeled appearance consequent, chiefly, upon the different degrees of fineness to which my mixture A and mixture B have been ground prior to mixing these two mixtures together.

llaving thus described my invention, What I claim as new, and desire to secure by Letters Patent, is

1. In the art of cnameling metal surfaces, the hereinbefore-named process, consisting of mixing and melting together the various ingredients of an enameling composition, cooling the same, and grinding the resulting mass to a certain degree of fineness, then separately mixing and melting together similar ingredients with coloring-matter addedthereto, cooling the same, and grinding this regrces of fineness and with the finest ground sulting mass to a different degree of fineness from thatto which the first mixture Was re- --ground mass or foundation-coating thereto,

and fixing it by subjecting the articles to heat in a suitable in uffle, mixing and melting together two like mixtures of the various ingredients of an enamelin g composition in separate crucibles, one having coloring-matter added thereto, cooling the same, and grinding the two resulting masses to different dein a moist condition, adding clay to the mass which is ground the finer of the two, and mixing the two ground masses together, in the proportions of about one part of the coarse-ground mass to three parts of the fineground mass, to a paste-like consistency, applyin the resulting product to the metal surfaces having the described foundation-coating, and subjecting the goods thus coated to heat in a suitable muffle, substantially as set forth.

In testimony that I claim the foregoing I have hereunto set my hand, at Sheboygan, in the county of Sheboygan and State of \Viscousin, in the presence of two Witnesses.

CARL A. i VOLLRATH.

Witnesses:

GUSTAV A. RIEss, FELIX BENFEY. 

